In conventional tubular string run-in and recovery operations, it is necessary to “make-up” or “break-out” the threaded connections between tubing, casing, or pipe joints near the rig floor. Generally, a first joint is positioned within the wellbore and a second joint is positioned above the first. A power operated tong is brought to the connection area of the two joints and rotated to either tighten or loosen the connection. A back-up tong may also be used to prevent rotation of the lower joint when the tong is making up or breaking out the upper joint.
Bringing the tong to the threaded connection may be a long, laborious, and even dangerous operation. The tong must first be brought to tubing, casing, or pipe string, which may require a considerable amount of calculation and effort. Often, one or more human operators must “man-handle” or manipulate the tong manually over the wellbore or other tubular location in order to properly position the tong on the tubular string. Due to the size and weight of tongs and the complexities of the make-up and break-out operations, this is not easily or quickly accomplished.
Systems have been designed to facilitate manipulation of the tong with respect to the rig floor and thus the tubular string. Some systems guide the tong on a track or rail mounted to the rig floor. This is not ideal, as the system occupies valuable rig-floor space and generally requires a permanent installation. Other systems use magnets to temporarily fix a tong support frame to the rig floor. For a variety of reasons, the prior art has shortcomings and a large amount of time and cost is used to move the tong to or from the tubing, casing or pipe connection before and after each make-up or break-out operation. A better tong positioning system is therefore required that is more safe, reliable, and efficient to operate.
This disadvantages of the prior art are overcome by the present invention, and an improved tong positioning system is hereinafter disclosed for reliability and safely moving a power tong with respect to a drilling rig between an active position wherein the powered tong is positioned for making up or breaking out a connection, and an inactive position wherein the power tong is spaced laterally from the connection.